JP5840847B2 - Glass substrate surface cleaning method and cleaning belt - Google Patents

Description

  The present invention relates to a glass substrate surface cleaning device and a glass substrate surface cleaning method for foreign matter (mainly glass cullet) adhered to a glass substrate generated in a cutting device for cutting a glass substrate, and particularly in a manufacturing process of a liquid crystal panel. Further, the present invention relates to a glass substrate surface cleaning apparatus and method for forming a liquid crystal panel before a polarizing plate attaching step.

  As a cleaning device and method for foreign matter (mainly glass cullet) attached to the glass substrate accompanying the substrate cutting device for cutting the glass substrate, currently, a device, method or abrasive using a vacuum suction means on the glass substrate is used. The apparatus and method used are known (for example, Patent Document 1 and Patent Document 2).

JP 2008-94690 A JP-A-2005-81297

  A problem to be solved by the present invention is a glass substrate surface cleaning apparatus and method having a cleaning function that can appropriately cope with various sizes (for example, a range of 10 μm to 1000 μm) of foreign matters (mainly glass cullet) existing on a glass substrate. Is to provide.

One aspect of the present invention, a cleaning belt having a glass substrate cleaning mechanism for removing a step of conveying the glass substrate in a first direction using a glass substrate support transfer mechanism, a foreign substance attached to the surface of the glass substrate a saw including a second step of sliding in the direction of crossing to the first direction on the surface of the glass substrate, wherein the cleaning belt, those a plurality of three-dimensional structure abrasive coating on the surface thereof A method for cleaning the surface of a glass substrate having a groove between three-dimensional structured abrasive coatings, wherein a plurality of glass substrates of the same production lot are examined for external width dimensions of foreign matters adhering to the surfaces of the glass substrates. A step of predicting a maximum value of the outer width dimension of the foreign matter in the manufacturing lot based on the measured outer width dimension of the foreign matter, and a groove width of the groove is a maximum of the predicted outer width dimension of the foreign matter. Less than A step of preparing the cleaning belt is, Ru glass substrate surface cleaning method der, which comprises a.
Another aspect of the present invention is a cleaning belt used in the glass substrate surface cleaning method.

According to the glass substrate surface Kiyoshi 掃方 method according to the present invention, a wide range of size on the glass substrate foreign matter (mainly glass cullet) can suitably be efficiently and reliably removed.

FIG. 1 is a perspective view showing an overall configuration of a glass substrate surface cleaning apparatus according to the present invention. FIG. 2 is a front view showing the overall configuration of the glass substrate surface cleaning apparatus according to the present invention. FIG. 3 is a plan view showing the relationship between the glass substrate transport direction (first direction, M) and the cleaning belt sliding direction (second direction, N) of the glass substrate surface cleaning apparatus according to the present invention. is there. FIG. 4 shows a part of a three-dimensional structured abrasive layer having a plurality of structured three-dimensional structured abrasive coatings provided on the surface of a cleaning belt provided in the glass substrate surface cleaning apparatus according to the present invention. FIG. FIG. 5 is a cross-sectional view taken along a cutting line XX in FIG. FIG. 6 shows an operational relationship between the foreign matter and the groove when the groove width of the groove provided in the three-dimensional structure abrasive layer of the cleaning belt is wider than the outer width of the foreign matter (glass cullet) adhering to the glass substrate surface. It is a schematic cross section. FIG. 7 shows the relationship between the foreign matter and the groove when the groove width of the groove provided in the three-dimensional structure abrasive layer of the cleaning belt is smaller than the outer width of the foreign matter (glass cullet) attached to the glass substrate surface. It is a schematic cross section.

Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and the general knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that design changes, improvements, and the like can be made as appropriate based on the above.
One embodiment of a glass substrate surface cleaning apparatus related to the present invention supports a glass substrate 50, and a glass substrate support transport mechanism 20 for transporting the glass substrate in a first direction (M in FIG. 3), A cleaning belt 11 is slid on the surface of the glass substrate in a second direction (N in FIG. 3) intersecting the first direction to remove the foreign matter 300 adhering to the surface of the glass substrate. A glass substrate surface cleaning device 100 having a glass substrate cleaning mechanism 10 having the cleaning belt 11 having a plurality of three-dimensional structure abrasive coatings 70 on the surface and grooves 60 positioned between the coatings. The glass substrate surface cleaning device 100 has a groove width 62 of the groove 60 wider than the outer width of the foreign material 300 attached to the glass substrate surface.
Here, “cleaning” means removing foreign matter (mainly glass cullet) on the glass substrate. The “external width dimension of foreign matter” means the maximum outer peripheral width of the foreign matter in the second direction (N in FIG. 3) in which the cleaning belt slides on the glass substrate. “Groove” means a gap formed between a three-dimensional structured abrasive coating and another three-dimensional structured abrasive coating adjacent thereto. “Groove width” means the distance between the upper part 72 of the three-dimensional structured abrasive coating and the upper part 72 of another three-dimensional structured abrasive coating adjacent thereto. Glass cullet means glass waste produced when a glass product is crushed, cut or the like.

  1 and 2 are books used for cleaning the surface of a glass substrate constituting a liquid crystal panel before a polarizing plate attaching step in a liquid crystal panel manufacturing step described in, for example, JP-A-2005-81297. 1 shows a cleaning device of the invention. In FIG. 1, the glass substrate surface cleaning apparatus 100 includes a glass substrate support transport mechanism 20 and a glass substrate cleaning mechanism 10. The glass substrate supporting / conveying device 20 has a carry-in roller shaft 21, a carry-out roller shaft 22 and a guide 23 for supporting the glass substrate from the lower surface side and carrying the glass substrate in a first direction (M in FIG. 3). . The glass substrate cleaning mechanism 10 is provided substantially above the center of the substrate support / conveyor 20 and has a cleaning belt 11 having an edgeless track, and driven guide pulleys 13 and 14 for rotating the cleaning belt while applying a predetermined tension. 15 and a drive guide pulley 12. The drive guide pulley is connected to the drive motor 18 to apply a drive force to the drive guide pulley. Moreover, the cleaning belt 11 is arrange | positioned in the direction (2nd direction, N in FIG. 3) which cross | intersects with respect to the conveyance direction (1st direction, M in FIG. 3) of a glass substrate.

As shown in FIG. 2, the cleaning belt 11 is disposed in contact with the upper surface of the glass substrate 50 when sliding, and a load load device 30 is provided immediately above the cleaning belt to apply a pressing force to the glass substrate to the cleaning belt. Has been placed. As the load device 30, any one such as an air blower type or a hydraulic type can be used as necessary. Load bearing can be adjusted in the range of 0.01 kg / cm ² of 3 kg / cm ^2.

  FIG. 3 shows the relationship between the glass conveyance direction (first direction, M in FIG. 3) and the cleaning belt sliding direction (second direction) in the glass substrate cleaning apparatus. As shown in FIG. 3, the sliding direction of the cleaning belt on the glass substrate (second direction, N in FIG. 3) intersects the transport direction of the glass substrate (first direction, M in FIG. 3). It is provided in the direction to do. The reason why the cleaning belts are arranged in such a manner is that the sliding surface can be widened with respect to the glass substrate and the impact when the glass substrate enters the cleaning belt is reduced. Specifically, the intersection angle θ (FIG. 3) is set to about 70 ° to 85 ° or about 95 ° to 110 °.

  The belt sliding speed and the glass substrate transport speed are determined in consideration of the productivity of the glass substrate and the degree of foreign matter removal. Specifically, the belt sliding speed in the second direction of the glass substrate (N in FIG. 3) can usually be adjusted in the range of 10 m to 500 m per minute, and the first direction of the glass substrate (M in FIG. 3). The conveyance speed can be adjusted in the range of usually 0.1 m to 10 m per minute. The value of the ratio of sliding speed / conveying speed is usually 2 to 100. Therefore, in the said glass substrate surface cleaning apparatus, foreign material removal is made | formed mainly by sliding of the cleaning belt of a 2nd direction (N in FIG. 3).

  4 and 5 show the cleaning belt 11 used in the glass substrate cleaning mechanism 10 as one embodiment of the present invention. As shown in FIGS. 4 and 5, the cleaning belt 11 used in the present invention has a plurality of three-dimensional structured abrasive coatings 70 and grooves 60 formed between the plurality of three-dimensional structured abrasive coatings on the surface. It comprises an abrasive layer 80 having a backing layer 90 that holds the abrasive layer on the back side of the surface.

  As described above, the abrasive layer is composed of the three-dimensional structure abrasive coating film 70 mounted on the upper surface of the backing layer 90 and the groove.

The geometric shape of the three-dimensional structure abrasive coating 70 is a cubic shape, a prismatic shape, a cylindrical shape, a conical shape, a pyramid shape, a truncated pyramid shape, a truncated cone shape, or the like. Selected from the group. Of these, preferred are those having the form of a truncated pyramid and truncated cone having a flat upper surface. This is because if the truncated pyramid / conical cone is used, the upper surface of the coating film of the three-dimensional abrasive is brought into surface contact with the glass substrate, and the removal of foreign matter adhering to the glass substrate is promoted.
The truncated pyramid / conical three-dimensional structure abrasive coating 70 is usually formed by precision molding. Here, “precision molding” has the same meaning as described in International Publication No. WO 98/39142, and a binder precursor containing abrasive grains is molded on the backing layer 90 using a manufacturing tool, Thereafter, the binder precursor is cured to form a three-dimensional shape.

The area of the upper portion 72 of each truncated pyramid thus precisely formed is 0.2 mm ² to 20 mm ² , preferably 1 mm ² to 10 mm ² . The lower portion 74 of the truncated pyramid has a surface that is up to 60% larger, more preferably up to 40%, most preferably up to 20% larger than the top. The height of the truncated pyramid / cone (H in FIG. 5) is 0.2 mm to 5 mm, more preferably 0.3 mm to 3 mm. The form of the three-dimensional abrasive coating 70 is finally determined in consideration of the state of the foreign matter to be removed, that is, the size of the foreign matter, the adhesion strength to the substrate, and the like.

The plurality of three-dimensional abrasive coatings 70 are regularly arranged on the upper surface of the backing layer 90 with regularity such as a lattice shape and a staggered shape at regular intervals in the second direction (N in FIG. 3). Thus, the arrangement is referred to as “structure” in the same meaning as described in International Publication No. WO 98/39142. Accordingly, in this specification, the abrasive layer and the abrasive coating film are referred to as “three-dimensional“ Called “structure” abrasive layer, three-dimensional “structure” abrasive coating.
The constituent material of the cleaning belt 11 includes a backing layer 90 and a three-dimensional structure abrasive layer 80, and the three-dimensional structure abrasive layer 80 includes abrasive grains and a binder.

  The backing layer 90 needs to be strong and durable so that the cleaning belt can last for a long time and the foreign matter removal (mainly glass cullet) 300 can be performed uniformly over the entire width of the belt. The cleaning belt 11 needs to be strong and flexible and flexible so that the cleaning belt 11 can be uniformly matched or adhered to the glass substrate. As a material for the backing layer, polymer film, paper, cloth, metal film, vulcanized fiber, laminates thereof, processed products, and the like can be used. Examples of the polymer film are a polyester film, a copolyester film, a polyimide film, a polyamide film, and the like. Examples of paper are those impregnated with a resin to improve strength. As an example of the cloth, a fiber selected from resin fibers, cotton fibers, glass fibers, and a combination of these can be used, and a woven fabric or a knit can be used. In addition, about a polymer film, in order to accelerate | stimulate adhesion | attachment with respect to the base material of a three-dimensional structure abrasive coating film, you may undercoat with materials, such as an ethylene acrylic acid copolymer.

  The three-dimensional structured abrasive layer 80 has an abrasive composite containing a binder matrix and abrasive grains dispersed therein as a constituent component.

  The size of the abrasive grains is preferably fine so as not to cause deep scratches on the glass surface. For example, the dimension is an average particle diameter of 0.01 to 10 μm, preferably 0.01 to 5 μm, more preferably 0.01 to 3 μm. Examples of abrasive grains suitable for the present invention include diamond, cubic boron nitride, cerium oxide, molten aluminum oxide, heat treated aluminum oxide, sol-gel aluminum oxide, silicon carbide, chromium oxide, silica, zirconia, alumina zirconia, iron oxide, garnet. , Calcium carbonate and mixtures thereof. Particularly preferred are diamond having a Mohs hardness of 6 or more, cubic boron nitride, aluminum oxide, silicon carbide, cerium oxide, and silica.

  The binder forms an abrasive layer by curing or gelation. Examples of preferred binders for the present invention include phenol resins, resol-phenol resins, aminoplast resins, urethane resins, epoxy resins, acrylate resins, polyester resins, vinyl resins, melamine resins, acrylated isocyanurate resins, urea-formaldehyde resins. , Isocyanurate resins, acrylated urethane resins, acrylated epoxy resins and mixtures thereof. The binder may be a thermoplastic resin.

  Particularly preferred are phenol resins, resol-phenol resins, epoxy resins, acrylate resins and urethane resins.

  The binder may be radiation curable. A radiation curable binder is any binder that can be at least partially cured or at least partially polymerized by irradiation energy. Depending on the binder used, energy sources such as heat, infrared, electron beam, ultraviolet irradiation or visible light irradiation are used.

  Typically, these binders are polymerized by a free radical mechanism. Preferably, these are acrylated urethanes, acrylated epoxies, aminoplast derivatives having an α, β-unsaturated carbonyl group, ethylenically unsaturated compounds, isocyanurate derivatives having at least one acrylate group, at least one It is selected from the group consisting of isocyanates having acrylate groups, and mixtures thereof.

  When the binder is cured by UV irradiation, a photoinitiator is required to initiate free radical polymerization. Examples of preferred photoinitiators for this purpose include organic peroxides, azo compounds, quinones, benzophenones, nitroso compounds, acrylic halides, hydrazones, mercapto compounds, pyrylium compounds, triacrylimidazoles, bisimidazoles, chloroalkyltriazines, benzoin ethers, Benzyl ketal, thioxanthone and acetophenone derivatives are included. Preferred photoinitiators are 2,2-dimethoxy-1,2-diphenyl-1-ethanone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one.

  When the binder is cured by visible light irradiation, the photoinitiator is required to initiate free radical polymerization. Examples of preferred photoinitiators for this purpose are U.S. Pat. No. 4,735,632, column 3, lines 25 to 4, line 10, columns 5-7, which are hereby incorporated by reference. Line, column 6, lines 1-35.

  The abrasive composite is formed from a slurry containing a plurality of abrasive grains dispersed in an uncured or ungelled binder. In curing or gelling, the abrasive composite is solidified, i.e., fixed to a predetermined shape and predetermined structure.

  The mixing ratio of the abrasive grains to the binder in the abrasive composite is generally about 50 to 1000 parts by weight of abrasive grains, preferably about 100 to 700 parts by weight of abrasive grains relative to 100 parts by weight of the binder. Range. This ratio varies depending on the type and size of the abrasive grains and the type of binder used.

  The abrasive composite may include materials other than abrasive grains and a binder. For example, conventional additives such as coupling agents, wetting agents, dyes, pigments, plasticizers, fillers, release agents, polishing aids and mixtures thereof.

  The abrasive composite can include a coupling agent. By adding a coupling agent, the viscosity of the slurry used to form the abrasive composite can be reduced. Examples of such coupling agents preferred for the present invention include organosilanes, zircoaluminates and titanates. The amount of coupling agent is generally less than 5% by weight, preferably less than 2% by weight of the abrasive.

  The groove 60 of the three-dimensional structure abrasive layer 80 of the cleaning belt 11 is formed between a plurality of three-dimensional structure abrasive coatings 70, and the shape of the groove is mounted on the upper surface of the backing layer 90 and structured. It becomes the outer periphery itself of the three-dimensional structure abrasive coating film 70. Thus, the depth of the groove is the same as the height of the truncated pyramid, 0.2 mm to 5 mm, and preferably 0.3 mm to 3 mm. The width of the groove is 0.3 mm or more, preferably 0.5 mm or more, and more preferably 1 mm or more.

  The groove size of the cleaning belt of the cleaning device according to the invention is determined in consideration of the size of the foreign matter (mainly glass cullet) to be removed. 6 and 7 schematically show the relationship between the foreign matter (glass cullet) during operation of the cleaning device and the groove 60 of the cleaning belt. When the groove width as shown in FIG. 6 is wider than the outer width of the foreign matter (glass cullet) adhering to the glass substrate surface, the upper part of the foreign matter (glass cullet) 300 on the glass substrate is first structured into an abrasive layer. In addition, the cleaning belt 11 is only in contact with the upper portions 72 of the three-dimensional structural abrasive coatings 70 (see FIG. 6A), but the cleaning belt 11 slides on the glass substrate, Due to the good flexibility, the foreign material (glass cullet) 300 is contained in the groove and fits into the groove (see FIG. 6B). Here, “foreign matter fits into the groove” means that at least a part of the foreign matter is included in the groove formed between the coating films of the three-dimensional structure and the three-dimensional structure is polished by sliding the belt. This refers to the state in which shearing force can be applied in the second direction (N in FIG. 3) from the material coating film.

  Thereafter, the foreign matter (glass cullet) in the groove collides with the side wall of the groove, that is, the side wall of the three-dimensional abrasive coating film 70 having good shape maintaining property (see FIG. 6C), and finally the foreign matter ( The glass cullet is removed from the glass substrate and moved in the groove (see FIG. 6D).

  On the other hand, when the groove width as shown in FIG. 7 is narrower than the external width dimension of the foreign material (glass cullet) 300 attached to the glass substrate surface, the upper part of the foreign material (glass cullet) on the glass substrate is initially three-dimensional of the polishing layer Even if the foreign matter (glass cullet) reaches the groove from the state where it is in contact with the upper portion 72 of the structural abrasive coating 70, the cleaning belt is slid without being included in the groove. The foreign substance (glass cullet) is not peeled off from the glass substrate and remains on the glass substrate only by sliding on the upper part of the polishing composite.

An example of a specific glass substrate surface cleaning method is as follows. The glass substrate surface cleaning apparatus according to the present invention is operated by the following procedure.
(1) First, sampling is performed for inspection of the occurrence of foreign matter on the glass substrate from the same production lot of the glass substrate 50, and the number of foreign matters and the external dimensions of the foreign matter are investigated for the sample to obtain information on the foreign matters. .
Here, the foreign matter occurrence state inspection can be performed by an inspection using an optical microscope, an inspection using an image processing apparatus, or the like.
(2) Predict the maximum value in the production lot of the outer width of the foreign material in the sliding direction (second direction) of the cleaning belt, select a cleaning belt having a groove width greater than that value, and attach it to the cleaning device .
(3) After placing the first glass substrate on the conveying device, the sliding direction of the cleaning belt with respect to the conveying direction (first direction, M in FIG. 3) in consideration of the work efficiency of the glass substrate surface cleaning, etc. The intersection condition (second direction, N in FIG. 3) is determined.
(4) After the cleaning belt is brought into close contact with the longitudinal end of the glass substrate, the glass substrate is transported in the transport direction (first direction, M in FIG. 3), and the cleaning belt is slid in the sliding direction (second And slide in the direction N) in FIG.
(5) After finishing the cleaning of the glass substrate surface of the first glass substrate, the second and subsequent glass substrates are arranged on the transfer device, and the following steps (3) and (4) are repeated.

Next, examples of the present invention will be described together with comparative examples.

(1) Test sample preparation 1) Examples 1 and 2
A cleaning belt having a three-dimensional structured abrasive layer suitable for use in the glass substrate surface cleaning method according to the present invention was produced by the following method.

  The abrasive coating liquid of the composition shown in Table 1 has a surface shape of a truncated quadrangular pyramid (square pyramid) having a square upper part of about 0.5 mm in height and about 2 mm in length by a knife coater. It was applied on a polypropylene shaped film (2MM-30-500) for forming a pattern having a distance of about 1.6 mm between the head quadrangular pyramids (square pyramid frustum), and calcium carbonate particles on the back surface. A 125 μm thick easily-adhesive polyester film having an anti-slip coating containing a urethane resin was laminated and irradiated with ultraviolet rays to cure the adhesive, thereby separating the abrasive film and the shaped film. This polishing film was heat-treated at 110 ° C. for 24 hours, and then cooled to room temperature to produce a polishing film. In addition, as an easy-adhesion process, it coats with an ethylene acrylic acid copolymer.

2) Example 3 and Comparative Example 1
Sumitomo 3M Co., Ltd. TRIZET (registered trademark) wrapping film 5 mil 3 micron aluminum oxide type 2

This abrasive has a surface shape of a truncated quadrangular pyramid (square pyramid) having a square upper surface with a height of about 0.35 mm and a side length of about 1.3 mm on the same film substrate as in Example 1. An abrasive layer is included, and aluminum oxide having a truncated quadrangular pyramid (square pyramid) distance of about 0.5 mm and an average particle diameter of 3 μm is included as abrasive grains.
(2) Evaluation test method and evaluation test result 1) Prepare a glass substrate, then rub the edges of two identical glass plates to generate a glass cullet, drop it on the glass substrate, and leave it for a while. Attached. The glass substrate was classified into a group in which the size of the glass cullet (outer width dimension) attached to the glass substrate was 1.5 mm or less and 0.5 mm or more, and a group less than 0.5 mm, and was subjected to the test.

  2) The polishing films of Examples 1, 2, 3 and Comparative Example 1 were processed into endless belts having a width of about 30 mm and a length of 2080 mm to prepare cleaning belts. This cleaning belt is attached to the cleaning device, the crossing angle θ (FIG. 3) is set to 80 °, the belt sliding speed is 100 m / min, and the surface with the cullet attached below is polished. The glass substrate was passed at a conveyance speed of about 6 m / min so as to hit the surface of the material. At this time, water was supplied from the back surface of the belt at a pressure of about 0.1 MPa, a load was applied to the belt, the abrasive surface was pressed against the surface of the glass substrate, and water was further supplied to the surface of the glass substrate to attach the cullet. The surface was cleaned. Table 2 shows the degree of cullet remaining on the glass surface after cleaning.

DESCRIPTION OF SYMBOLS 10 Glass substrate cleaning mechanism 11 Cleaning belt 12 Drive guide pulley 13, 14, 15 Drive guide pulley
18 drive motor 20 glass substrate support and conveyance mechanism 21 carry-in roller shaft 22 carry-out roller shaft 23 guide 30 load applying device 50 glass substrate 60 groove 62 groove width 70 three-dimensional structure abrasive coating 72 (of three-dimensional structure abrasive coating) Upper part 74 Lower part of three-dimensional structure abrasive coating film 80 Three-dimensional structure abrasive layer 90 Backing layer 100 Glass substrate surface cleaning device 300 Foreign matter (mainly glass cullet)

Claims (2)

A step of conveying the glass substrate in a first direction using a glass substrate support transfer mechanism, a cleaning belt having a glass substrate cleaning mechanism for removing foreign matters adhering to the surface of the glass substrate, the surface of the glass substrate look including the step of sliding in a second direction intersecting to said first direction on said cleaning belt, they three-dimensional structured abrasive material coating and a plurality of three-dimensional structure abrasive coating on the surface thereof A glass substrate surface cleaning method having a groove between films ,
For a plurality of glass substrates in the same production lot, a step of examining the outer width of foreign substances attached to the surfaces of the glass substrates,
A step of predicting a maximum value of the outer width dimension of the foreign matter in the manufacturing lot based on the outer width dimension of the foreign matter investigated;
A step of preparing the cleaning belt, wherein the groove width of the groove is equal to or greater than the predicted maximum width of the foreign substance;
The glass substrate surface cleaning method characterized by including . The cleaning belt used for the glass substrate surface cleaning method of Claim 1.